Differentiation between cholesteatoma and inflammatory process of the middle ear, based on contrast-enhanced computed tomography imaging

Clinical features and literature review related to the material differences in thread rhinoplasty: Two case reports

BACKGROUND

Thread rhinoplasty can trigger a reaction to thread material, which is a foreign body. We compared clinical features induced by absorbable and non-absorbable threads following thread rhinoplasty.

CASE SUMMARY

Two patients who underwent different thread materials showed different clinical courses and different Hounsfield unit (HU) values in computed tomography. Patients with absorbable thread showed high HU values similar to a metallic material, and the HU value of inflammation was similar to vascular tissues with a lot of water (250). In the intraoperative field, absorbable thread materials and micro-abscesses were observed. In contrast, in the case of a non-absorbable thread, an object presumed to be thread was seen on the computed tomography (CT), and the HU value of inflammatory tissues was less than 100. In both patients, post-operative HU decreased to less than 100 and the clinical course improved. In both cases, histopathologic findings revealed foreign body granuloma associated with inflammation.

CONCLUSION

Absorbable threads were more aggressive and are more easily detected on CT.

Radiomics of high-resolution computed tomography for the differentiation between cholesteatoma and middle ear inflammation: effects of post-reconstruction methods in a dual-center study

Objectives

To evaluate the performance of radiomic features extracted from high-resolution computed tomography (HRCT) for the differentiation between cholesteatoma and middle ear inflammation (MEI), and to investigate the impact of post-reconstruction harmonization and data resampling.

Methods

One hundred patients were included in this retrospective dual-center study: 48 with histology-proven cholesteatoma (center A: 23; center B: 25) and 52 with MEI (A: 27; B: 25). Radiomic features (co-occurrence and run-length matrix, absolute gradient, autoregressive model, Haar wavelet transform) were extracted from manually defined 2D-ROIs. The ten best features for lesion differentiation were selected using probability of error and average correlation coefficients. A multi-layer perceptron feed-forward artificial neural network (MLP-ANN) was used for radiomics-based classification, with histopathology serving as the reference standard (70% of cases for training, 30% for validation). The analysis was performed five times each on (a) unmodified data and on data that were (b) resampled to the same matrix size, and (c) corrected for acquisition protocol differences using ComBat harmonization.

Results

Using unmodified data, the MLP-ANN classification yielded an overall median area under the receiver operating characteristic curve (AUC) of 0.78 (0.72–0.84). Using original data from center A and resampled data from center B, an overall median AUC of 0.88 (0.82–0.99) was yielded, while using ComBat harmonized data, an overall median AUC of 0.89 (0.79–0.92) was revealed.

Conclusion

Radiomic features extracted from HRCT differentiate between cholesteatoma and MEI. When using multi-centric data obtained with differences in CT acquisition parameters, data resampling and ComBat post-reconstruction harmonization clearly improve radiomics-based lesion classification.

Key Points

• Unenhanced high-resolution CT coupled with radiomics analysis may be useful for the differentiation between cholesteatoma and middle ear inflammation.

• Pooling of data extracted from inhomogeneous CT datasets does not appear meaningful without further post-processing.

• When using multi-centric CT data obtained with differences in acquisition parameters, post-reconstruction harmonization and data resampling clearly improve radiomics-based soft-tissue differentiation.

Clinical analysis and nonsurgical management of 11 dogs with aural cholesteatoma

BACKGROUND

Aural cholesteatomas, also called tympanokeratomas, are destructive and expansile growths of keratinizing epithelium that develop in the middle ear. They have been reported sporadically in dogs, and surgery is usually the recommended treatment.

OBJECTIVES

To describe the common clinical, radiological and histological findings of cholesteatoma; to report on the outcome of conservative management.

ANIMALS

Eleven dogs (13 ears) with cholesteatomas.

METHODS AND MATERIALS

Medical records were reviewed for dogs diagnosed with cholesteatoma between 2012 and 2018. All dogs had computed tomography (CT) and/or magnetic resonance imaging (MRI) followed by trans-canal endoscopic procedure (TEP) for removal and biopsy of middle ear lesions. Dogs were then treated with in-clinic flushing initially weekly tapered to monthly, as well as at-home ear cleaning and application of topical otic steroid medication, initially daily then tapered to once or twice weekly.

RESULTS

Nine dogs had a history of chronic otitis externa; head tilt or facial paralysis was present in seven and four cases, respectively. Otic examination identified a protruding nodule in seven ears. CT demonstrated soft tissue-like material in 12 bullae and expansion in seven bullae. MRI revealed minimally contrast-enhancing bulla contents in 12 ears. Post-TEP and with maintenance medical treatment, nine ears had no further signs of middle ear disease during a mean follow-up of 27.9 months.

CONCLUSIONS AND CLINICAL IMPORTANCE

The results suggest that otitis externa may not necessarily precede cholesteatoma in all dogs. MRI appears to be more sensitive than CT for identifying cholesteatomas. Conservative treatment of cholesteatomas could be useful before or as an alternative to surgery.

Aggressiveness of pediatric cholesteatoma. Do we have an evidence?

To compare pediatric and adult patients, affected by cholesteatoma for the clinical presentation, disease extent and final outcome. This is a prospective study in which 60 cases of unsafe chronic suppurative otitis media with cholesteatoma were included. These cases were divided into two groups of 30 cases each on the basis of age. All patients were subjected to detailed clinical examination. A high resolution computed tomography of the temporal bone was done in all the cases. An innovative grading system was devised to grade the disease. The patients were subjected to canal wall down mastoidectomy and were evaluated postoperatively for resolution of the symptoms, hearing and cavity problems. Granulation tissue along with cholesteatoma was more common among children (p < 0.01), whereas cholesteatoma alone was more common among adults. There was excellent correlation between the radiological and surgical findings. It was seen that higher the grade of the disease, the greater was the risk of complications and recidivism (p < 0.05). Recidivism was significantly higher in children (p < 0.05) whereas complications were equally common in both the groups. Hearing improvement was equivocal in both groups. Presence of granulation tissue along with cholesteatoma in children causes more aggressive disease with higher recidivism rate.

MRI findings of a middle ear cholesteatoma in a dog

This article describes the MRI features of a middle ear cholesteatoma in an 8 yr old flat-coated retriever. Physical examination revealed pain on opening the jaw, and otoscopic examination showed tympanic membrane rupture associated with hyperplastic tissue at the entrance of the middle ear. Standard MRI sequences allowed for the identification of a severely expanded bulla containing material that was isointense to brain tissue on T1-weighted images and of mixed intensity on T2-weighted and fluid-attenuated inversion recovery sequences. No postcontrast enhancement of the content was present, but the lining of the bulla was partially enhanced. The images allowed evaluation of the surgical margins and the secondary changes due to the expansion of the mass. Surgery was performed and histopathology confirmed the presumptive diagnosis of cholesteatoma. In the present case, MRI appeared to serve as a good alternative to computed tomography for the diagnosis of cholesteatoma.

Residual cholesteatoma: prevalence and location. Follow-up strategy in adults

OBJECTIVES

To assess prevalence and location of residual cholesteatoma following closed "canal wall up" tympanoplasty (CWUT). The evolution of follow-up strategy is discussed.

PATIENTS AND METHODS

A retrospective study was run in adults operated on by CWUT for middle-ear cholesteatoma and who had undergone second look surgery and/or postoperative radiology (CT-scan, diffusion-weighted MRI).

RESULTS

One hundred and nine patients (113 ears) underwent the procedure. Mean follow-up was 48 months (range, 24-96 months). Twenty-nine residual cholesteatomas were found (25%), including 11 located in the anterior attic (38%). Follow-up included 77 second look operations (70%), and 71 radiological examinations (62 CT-scans and nine diffusion-weighted MRIs). Second look surgery was without benefit for the patient (no residual, no ossiculoplasty) in one third of cases.

CONCLUSION

Residual cholesteatoma in the anterior attic is a problem in CWUT. When postoperative auditory results are good, second look surgery should not be systematic but guided by high quality imaging.

Predictive validity of MRI in detecting and following cholesteatoma

High recurrence rate of the middle ear cholesteatoma requires regular postoperative follow-up. This study evaluated data from the patients investigated with DW MRI to ascertain (1) the strength of the technique in detecting primary, and residual recurrent cholesteatoma, and (2) its accuracy in differentiating cholesteatoma from postoperative tissue changes. The diagnostic accuracy of two different DW imaging (EPI and non-EPI) techniques was evaluated. The data have been collected prospectively from 33 consecutive patients with either primary cholesteatoma, or with suspicious symptoms for potential cholesteatoma recurrence. The findings from non-EPI (HASTE) DW MR and EPI DW MR images were blindly compared with those obtained during a primary or secondary surgery. Preoperative non-EPI (HASTE) DWI pointed to a cholesteatoma in 25 out of 33 patients. In this subgroup, cholesteatoma were confirmed also by the surgery. In five cases, the non-EPI (HASTE) DWI did not show a cholesteatoma in the temporal bone, which agreed with the surgical findings. Three misclassifications were made by non-EPI (HASTE) DWI, all in the subgroup of patients indicated for primary surgery. The resulting pooled sensitivity of non-EPI (HASTE) DW imaging for diagnosing cholesteatoma in our study amounted to 96.15% (95% confidence interval (CI) 80.36-99.9), specificity was 71.43% (95% CI 29.04-96.33). Positive predictive value was 92.59% (95% CI 75.71-99.09) and negative predictive value 83.33% (95% CI 35.88-99.58). In conclusion, we recommend the non-EPI (HASTE) DW MRI as a valid method for diagnosing cholesteatoma and follow-up after cholesteatoma surgery.

Usefulness of computed tomography Hounsfield unit density in preoperative detection of cholesteatoma in mastoid ad antrum

PURPOSE

This study was performed to evaluate the usefulness of Hounsfield unit (HU) to better distinguish cholesteatoma from other inflammatory conditions in the mastoid ad antrum before primary mastoid surgery.

MATERIALS AND METHODS

We enrolled 82 patients who underwent tympanomastoidectomy for treatment of chronic otitis. Forty-one patients were pathologically diagnosed with cholesteatoma, whereas the others were diagnosed with inflammatory granulation. These lesions were confirmed, and HU was measured in preoperative computed tomography. The difference in HU between cholesteatoma and non-cholesteatoma tissues was analyzed, and the improvement in the diagnosis of cholesteatoma after inclusion of HU data was calculated.

RESULTS

The HU was calculated as 42.68 ± 24.42 in the cholesteatoma group and 86.07 ± 26.50 in the non-cholesteatoma group. The differences between the 2 groups were statistically different (Student t test, P < .01). By applying the HU, the sensitivity (51.2%-80.5%), specificity (80.5%-87.8%), positive predictive value (72.4%-86.8%), and negative predictive value (62.3%-81.8%) to diagnose cholesteatoma improved.

CONCLUSIONS

The HU density was found to be statistically different between cholesteatoma and inflammatory granulation tissue in mastoid antrum. An improved diagnosis of cholesteatoma was achieved after adjusting for the HU.